TY - JOUR T1 - Delay in Diagnosis of Diabetes Mellitus Due to Inaccurate Use of Hemoglobin A<sub>1C</sub> Levels JF - The Journal of the American Board of Family Medicine JO - J Am Board Fam Med SP - 93 LP - 96 DO - 10.3122/jabfm.2007.01.060086 VL - 20 IS - 1 AU - Jason G. Arnold AU - Howard J. McGowan Y1 - 2007/01/01 UR - http://www.jabfm.org/content/20/1/93.abstract N2 - Testing of hemoglobin A1C (HbA1C) levels has become widespread in the management of patients with diabetes mellitus. Since the 1980s, it has proven to be an invaluable tool correlating with a patient’s average blood glucose levels as well as with their disease morbidity. Clinicians often base treatment decisions and make adjustments depending on a patient’s HbA1C level. As useful as the HbA1C is, it does have notable limitations. A number of conditions can lead to a falsely elevated or a falsely low HbA1C level. When one of these conditions is present, it is important to recognize the inaccuracy of the HbA1C test to prevent a delay or error in the diagnosis or care of patients with diabetes mellitus. It is also important to be aware of alternative methods of monitoring a patient’s diabetes such as a fructosamine assay or home and office blood glucose measurements. Presented is the case of a patient with diabetes mellitus and hereditary spherocytosis, a condition that interfered with her HbA1C value and resulted in a delay in her care. ER -